Anales de Química de la RSEQ

Metal-nitrogen-carbon single-site electrocatalysts are one of the most promising alternatives to precious metals in proton exchange membrane fuel cells or CO₂ electrolysers. Their synthesis, however, is hindered by the high temperature pyrolysis, which leads to the formation of nanoparticles and to low active site number and accessibility. Therefore, synthetic strategies that decouple high-temperature pyrolysis and single site loading in a porous nitrogen-doped scaffold, are sought after. In this perspective, we discuss the recent developments in the field of Fe-N-C materials, with a focus in decoupled synthetic techniques via Zn and Mg exchange to avoid Fe aggregation.

 

Keywords: Single atom catalysts, electrochemistry, electrocatalysts, oxygen reduction reaction, CO2 reduction

The chemistry of transition metal complexes with monoanionic bidentate ligands k²-Si,L and/or tridentate k³-Si,L₂—where Si represents a silyl group and L ligands with neutral s-donor groups—has gained increasing interest in recent years. This review highlights the advances achieved through the application of these complexes as catalysts in essential processes, such as the hydrogenation and hydrosilylation of unsaturated molecules.

Keywords: homogeneous catalysis, polydentate ligands, metal-silyl complexes, hydrogenation, hydrosilylation

Despite the fact that the first attempts to create luminescent plants failed, luminescent petunias went on sale in the USA in April 2024. Light emitting chemical reactions are a little-known part of the chemistry subject for students, as photochemical processes are not covered at pre-university level beyond photosynthesis reactions. By introducing luminescent plants as a practical application of chemistry and biotechnology, this could be a further attraction in the didactics of the subject, as well as an attempt to approach sustainable development goal 7: accessible and clean energy, proposed as part of the 2030 Agenda by the United Nations.

Keywords: Glowing plants, Bioluminiscence, Green Green Fluorescent Protein (GFP), Application of chemistry, Sustainable development 2030 Agenda

It is well known that if a lit candle is covered with a glass, the flame quickly weakens and, after a few sec- onds goes out. Since this occurs by limiting the amount of air available for combustion, most people who observe this experiment conclude that the candle goes out due to the depletion of the oxygen trapped in the glass. Research conducted by numerous authors has revealed that this idea is deeply ingrained in students at various educational levels, and even among postgraduates and science teachers. This article presents a simple and reliable method that effectively demonstrates that combustion in a closed space always ceases before all the available oxygen is consumed.

Keywords: combustion in a closed space, glass that covers a candle, steel wool, mole fraction of oxygen

All passengers traveling by plane, are informed by cabin crew how to put on oxygen masks in case of an emergency depressurization. But where does this oxygen come from? Many people think it is stored in tanks. However, it comes from small chemical oxygen generators (COGs, oxygen Candle), containing sodium chlorate, a reagent that decomposes thermally, generating oxygen.  From a didactic point of view, the chemical reactions involved in oxygen generators in confined spaces and CO₂ capture systems in spaces without air renewal are shown.

Keywords: oxygen mask, Oxygen generator, sodium chlorate, CO2 capture